Well, the action are currently bind with a ENTER keypress or onChange (when is't a datefield or a combo)... also, as you can see in the code, I put params search with field name and value in the extraparams of the datastore and reload it. So by example on a PHP page receiving that query you can do.

I used your implementations above. Sadly it doesn't work with a stateful Grid.
The problem pops up when columnresize is fired at start. Then the column.filterField is undefined.
I don't know if this has worked in the past but with 4.0.2a it doesn't